the knoevenagel condensation of aromatic aldehydes with barbituric acid, dimedone and malononitrile occurred in the presence of bf3/nano-γ-al2o3 at room temperature in ethanol. this catalyst is characterized by powder x-ray diffraction (xrd), fourier transform infrared spectroscopy (ft-ir), thermal gravimetric analysis (tga), field emission scanning electron microscopy (fesem) and energy-disper...

In order to develop a rapid and effective analysis method for studying integrally the main constituents in the medicinal materials and their extracts, discriminating the extracts from different extraction process, comparing the categories of chemical constituents in the different extracts and monitoring the qualities of medicinal materials, we applied Fourier transform infrared spectroscopy (FT...

www.spec t roscopyon l i ne . com T he concept of step-scan mid-infrared inter ferometr y dates back to the 1960s when the first optoelectronically controlled step-scan interferometer was reported (1). In contrast to the linear change of the optical path difference (retardation) in a conventional continuous-scan interferometer, the retardation changes stepwise in a step -scan Fourier transform–...

Over the last few decades, infrared (IR) spectroscopy has been recognized as a useful tool to obtain quantitative and qualitative information on IR active materials and bio-materials, with particular emphasis to polymer chemistry and organic chemistry. Nowadays, thanks to technological evolution, the possibilities offered by vibrational spectroscopy (e.g. IR and Raman spectroscopy) are much bro...

self-association of alcohols; including ethanol, methanol, cyclopentanol and octanol in separate mixtures with inert solvents have been studied using ft-ir spectroscopy. except for the band at 3640 cm–1 in the ir spectrum of the alcohols which is due to the monomer species, the presence of other bands in the region of stretching vibrational frequencies of oh (3100-3700 cm–1) are attributed to t...